526 research outputs found
In vitro analysis of the invasive phenotype of SUM 149, an inflammatory breast cancer cell line
BACKGROUND: Inflammatory breast cancer (IBC) is the most lethal form of locally invasive breast cancer known. However, very little information is available on the cellular mechanisms responsible for manifestation of the IBC phenotype. To understand the unique phenotype of IBC, we compared the motile and adhesive interactions of an IBC cell line, SUM 149, to the non-IBC cell line SUM 102. RESULTS: Our results demonstrate that both IBC and non-IBC cell lines exhibit similar adhesive properties to basal lamina, but SUM 149 showed a marked increase in adhesion to collagen I. In vitro haptotaxis assays demonstrate that SUM 149 was less invasive, while wound healing assays show a less in vitro migratory phenotype for SUM 149 cells relative to SUM 102 cells. We also demonstrate a role for Rho and E-cadherin in the unique invasive phenotype of IBC. Immunoblotting reveals higher E-cadherin and RhoA expression in the IBC cell line but similar RhoC expression. Rhodamine phalloidin staining demonstrates increased formation of actin stress fibers and larger focal adhesions in SUM 149 relative to the SUM 102 cell line. CONCLUSION: The observed unique actin and cellular architecture as well as the invasive and adhesive responses to the extracellular matrix of SUM 149 IBC cells suggest that the preference of IBC cells for connective tissue, possibly a mediator important for the vasculogenic mimicry via tubulogenesis seen in IBC pathological specimens. Overexpression of E-cadherin and RhoA may contribute to passive dissemination of IBC by promoting cell-cell adhesion and actin cytoskeletal structures that maintain tissue integrity. Therefore, we believe that these findings indicate a passive metastatic mechanism by which IBC cells invade the circulatory system as tumor emboli rather than by active migratory mechanisms
Variations of mesozooplankton composition in a eutrophicated semi-enclosed system (Encerrada Bay, Tierra del Fuego, Argentina)
Tidal effects on short-term mesozooplankton distribution in small channels of a temperate-turbid estuary, Southwestern Atlantic
Influence of Experimental Thermal Shifts and Overcrowding on Fecundity in Wild Females of Acartia Tonsa of the BahĂa Blanca Estuary
Magnetism, FeS colloids, and Origins of Life
A number of features of living systems: reversible interactions and weak
bonds underlying motor-dynamics; gel-sol transitions; cellular connected
fractal organization; asymmetry in interactions and organization; quantum
coherent phenomena; to name some, can have a natural accounting via
interactions, which we therefore seek to incorporate by expanding the horizons
of `chemistry-only' approaches to the origins of life. It is suggested that the
magnetic 'face' of the minerals from the inorganic world, recognized to have
played a pivotal role in initiating Life, may throw light on some of these
issues. A magnetic environment in the form of rocks in the Hadean Ocean could
have enabled the accretion and therefore an ordered confinement of
super-paramagnetic colloids within a structured phase. A moderate H-field can
help magnetic nano-particles to not only overcome thermal fluctuations but also
harness them. Such controlled dynamics brings in the possibility of accessing
quantum effects, which together with frustrations in magnetic ordering and
hysteresis (a natural mechanism for a primitive memory) could throw light on
the birth of biological information which, as Abel argues, requires a
combination of order and complexity. This scenario gains strength from
observations of scale-free framboidal forms of the greigite mineral, with a
magnetic basis of assembly. And greigite's metabolic potential plays a key role
in the mound scenario of Russell and coworkers-an expansion of which is
suggested for including magnetism.Comment: 42 pages, 5 figures, to be published in A.R. Memorial volume, Ed
Krishnaswami Alladi, Springer 201
Scaffolding development and the human condition
This paper addresses the concept of semiotic scaffolding by considering it in light of questions arising from the contemporary challenge to the humanities. This challenge comes from a mixture of scientistic demands, opportunism on the part of Western governments in thrall to neo-liberalism, along with crass economic utilitarianism. In this paper we attempt to outline what a theory of semiotic scaffolding may offer to an understanding of the humanitiesâ contemporary role, as well as what the humanities might offer to the elucidation of semiotic scaffolding. We argue that traditional humanist positions adopted in defence of the humanities fail to articulate the enhancement of humanity that semiotic scaffolding represents. At the same time, we note that the concept of scaffolding is sometimes in danger of taking on a functionalist perspective which understanding the humanities modus operandi is likely to dispel. Putting forward these arguments, we draw on the work of Peirce, Cassirer and Sebeok in elucidating the structural and âfuture-orientatedâ benefits of the scaffolding process as it suffuses the humanities
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